AccountabilityClear ownership for decisions, controls, residual risk and outcomes.AssuranceStructured confidence that claims about a system are supported by evidence.Capability thresholdA measurable boundary that triggers stronger governance requirements.Control ownerThe person or function accountable for control design, operation and evidence.Decision rightExplicit authority to approve, reject, escalate or stop a material action.Evaluation gateA decision checkpoint requiring evaluation evidence before progression.Frontier modelA model at or near the leading edge of relevant capabilities.Human oversightMeaningful human authority to observe, intervene, restrict or stop a system.Kill switchA mechanism designed to terminate or isolate system operation under defined conditions.Model access tierA governance class defining who may access a model and under what controls.Residual riskRisk remaining after controls are applied and verified.Safety caseA structured argument connecting claims, evidence and reasoning about acceptable risk.